Retention of pesticides and nutrients in a vegetated buffer root zone compared to soil with low biological activity

A laboratory study has been conducted to examine the retention processes of nitrogen and pesticides through vegetated buffer zones compared to bare soil. Soil columns with low biological activity and vegetation columns with normal biological activity were tested. Pesticides frequently used in vegetable production (namely aclonifen, azinphos-methyl, chlorpropham, diazinon, dimethoate, fluazinam, iprodione, linuron, metalaxyl, metamitron, metribuzin and propachlor) equal to 1/50 to 1/5 part of recommended doses, and nutrients equal to 1, 5 and 20 mg N/L and 0.2 mg P/L, were added. The pesticide retention was more than 60% for all pesticides, except dimethoate, with a retention of about 30% in columns with low microbial activity. Biological transformation and plant uptake were important for removal of nitrogen and organic matter. Nitrogen retention was high (over 90%) in vegetation columns. Plant uptake and phosphorus content in soil were important for phosphorus retention.